It is common practice on many computers to use a device known as a mouse for moving a pointer or cursor on the CRT display of the computer into various positions on the display for one or more purposes. Such a mouse is a small hand-held box-like device which is coupled by a cable to the computer and which requires a flat, smooth surface over which the mouse can move in an X direction, a Y direction, or in a combination of X and Y directions.
While a mouse of the type described is satisfactory for many applications and uses of a computer, it has been found to be limiting in the sense that a mouse requires the full use of one hand in order to be moved over a surface for controlling the pointer on the CRT display of the computer. This may be a drawback when it is desired to use both hands on the keyboard of the computer and when it is desired not to shift the eyes from the display to the mouse. Thus, it would be advantageous if the hands could be used at all times on the keyboard while still having the advantages of a mouse.
When using a mouse, the surface over which the mouse must move is an essential part of the system. At times, portable computers are placed on the lap of the user and no such surface for the mouse is available. Thus, for a conventional mouse, the surface must be provided; otherwise, the mouse cannot be used with the computer while it is lap-mounted or in cases where no adjacent surface is available for operating the mouse.
Because of these and other drawbacks associated with a conventional mouse, a need has existed for improved apparatus which allows for the advantages of a mouse while allowing the hands to remain on the keyboard and without requiring a flat work surface of the type now required for a conventional mouse. The mechanism of the present invention satisfies this need.